1. Field of the Invention
The invention relates to turbomachine blades, such as those of a compressor or fan, which are made of a fiber-reinforced composite material. Such blades are geometrically simplified by the absence of platforms and struts, and have the advantage of substantially reducing the mass of the bladed rotor assembly, which is very important in the case of large diameter turbomachines.
2. Discussion of the Background
However, one difficulty which arises in the manufacture of turbomachine blades of composite materials is that, in spite of having high tensile strength, the fibers used in the reinforcement of the material are fragile and weak under compression or shear. Problems then arise with the transfer of loads from the blades, which are of composite material, to the rotor disc, which is metallic, without damage to the fibers.
The root of this type of blade is usually in the form of a dovetail or a bulb, and the fibers of the aerodynamic part of the blade extend into the root, the fibers moving apart within the root. It is necessary, in order to obtain a good resistance to centrifugal force, to ensure the integrity of the composite material of the blade in this area of the root.